Pain is the most common symptom for which patients seek medical advice and treatment. Pain can be acute or chronic. While acute pain is usually self-limited, chronic pain persists for 3 months or longer and can lead to significant changes in a patient's personality, lifestyle, functional ability and overall quality of life (K. M. Foley, Pain, in Cecil Textbook of Medicine 100-107 (J. C. Bennett and F. Plum eds., 20th ed. 1996)).
Moreover, chronic pain can be classified as either nociceptive or neuropathic. Nociceptive pain includes tissue injury-induced pain and inflammatory pain such as that associated with arthritis. Neuropathic pain is caused by damage to the peripheral or cental nervous system and is maintained by aberrant somatosensory processing. There is a large body of evidence relating activity at both Group I metabotropic glutamate receptors, i.e., metabotropic glutamate receptor 1 (“mGluR1”) and metabotropic glutamate receptor 5 (“mGluR5”) (M. E. Fundytus, CNS Drugs 15:29-58 (2001)), and vanilloid receptors (“VR1”) (V. Di Marzo et al., Current Opinion in Neurobiology 12:372-379 (2002)) to pain processing. Inhibiting mGluR1 or mGluR5 reduces pain, as shown by in vivo treatment with antibodies selective for either mGluR1 or mGluR5, where neuropathic pain in rats was attenuated (M. E. Fundytus et al., NeuroReport 9:731-735 (1998)). It has also been shown that antisense oligonucleotide knockdown of mGluR1 alleviates both neuropathic and inflammatory pain (M. E. Fundytus et al., Brit. J. Pharmacol. 132:354-367 (2001); M. E. Fundytus et al., Pharmacol., Biochem. & Behavior 73:401-410 (2002)). Small molecule antagonists for mGluR5-attenuated pain in in vivo animal models are disclosed in, e.g., K. Walker et al., Neuropharmacol. 40:1-9 (2000) and A. Dogrul et al., Neurosci. Let. 292:115-118 (2000)).
Nociceptive pain has been traditionally managed by administering non-opioid analgesics, such as acetylsalicylic acid, choline magnesium trisalicylate, acetaminophen, ibuprofen, fenoprofen, diflusinal, and naproxen; or opioid analgesics, including morphine, hydromorphone, methadone, levorphanol, fentanyl, oxycodone, and oxymorphone. Id. In addition to the above-listed treatments, neuropathic pain, which can be difficult to treat, has also been treated with anti-epileptics (e.g. gabapentin, carbamazepine, valproic acid, topiramate, phenytoin), NMDA antagonists (e.g. ketamine, dextromethorphan), topical lidocaine (for post-herpetic neuralgia), and tricyclic antidepressants (e.g. fluoxetine, sertraline and amitriptyline).
UI is uncontrollable urination, generally caused by bladder-detrusor-muscle instability. UI affects people of all ages and levels of physical health, both in health care settings and in the community at large. Physiologic bladder contraction results in large part from acetylcholine-induced stimulation of post-ganglionic muscarinic-receptor sites on bladder smooth muscle. Treatments for UI include the administration of drugs having bladder-relaxant properties, which help to control bladder-detrusor-muscle overactivity. For example, anticholinergics such as propantheline bromide and glycopyrrolate, and combinations of smooth-muscle relaxants such as a combination of racemic oxybutynin and dicyclomine or an anticholinergic, have been used to treat UI (See, e.g., A. J. Wein, Urol. Clin. N. Am. 22:557-577 (1995); Levin et al., J. Urol. 128:396-398 (1982); Cooke et al., S. Afr. Med. J. 63:3 (1983); R. K. Mirakhur et al., Anaesthesia 38:1195-1204 (1983)). These drugs are not effective, however, in all patients having uninhibited bladder contractions.
None of the existing commercial drug treatments for UI has achieved complete success in all classes of UI patients, nor has treatment occurred without significant adverse side effects. For example, drowsiness, dry mouth, constipation, blurred vision, headaches, tachycardia, and cardiac arrhythmia, which are related to the anticholinergic activity of traditional anti-UI drugs, can occur frequently and adversely affect patient compliance. Yet despite the prevalence of unwanted anticholinergic effects in many patients, anticholinergic drugs are currently prescribed for patients having UI. The Merck Manual of Medical Information 631-634 (R. Berkow ed., 1997).
Certain pharmaceutical agents have been administered for treating addiction. U.S. Pat. No. 5,556,838 to Mayer et al. discloses the use of nontoxic NMDA-blocking agents co-administered with an addictive substance to prevent the development of tolerance or withdrawal symptoms. U.S. Pat. No. 5,574,052 to Rose et al. discloses co-administration of an addictive substance with an antagonist to partially block the pharmacological effects of the addictive substance. U.S. Pat. No. 5,075,341 to Mendelson et al. discloses the use of a mixed opiate agonist/antagonist to treat cocaine and opiate addiction. U.S. Pat. No. 5,232,934 to Downs discloses administration of 3-phenoxypyridine to treat addiction. U.S. Pat. Nos. 5,039,680 and 5,198,459 to Imperato et al. disclose using a serotonin antagonist to treat chemical addiction. U.S. Pat. No. 5,556,837 to Nestler et al. discloses infusing BDNF or NT-4 growth factors to inhibit or reverse neurological adaptive changes that correlate with behavioral changes in an addicted individual. U.S. Pat. No. 5,762,925 to Sagan discloses implanting encapsulated adrenal medullary cells into an animal's central nervous system to inhibit the development of opioid tolerance. U.S. Pat. No. 6,204,284 to Beer et al. discloses racemic (±)-1-(3,4-dichlorophenyl)-3-azabicyclo[3.1.0]hexane for use in the prevention or relief of a withdrawal syndrome resulting from addiction to drugs and for the treatment of chemical dependencies. Glutamate release is enhanced during opioid withdrawal (K. Jhamandas et al., J. Neurosience 16:2758-2766 (1996)). Recent evidence suggests a role for Group I mGluRs in opioid tolerance and dependence. An interaction between opioids and mGluRs was demonstrated when it was shown that an antagonist at Group I mGluRs significantly attenuated withdrawal symptoms in opioid-dependent rats (M. E. Fundytus et al., Brit. J. Pharmacol. 113:1215-1220 (1994)). More recent results show that antisense oligonucleotide knockdown of mGluR1 reduces protein kinase C activity (M. E. Fundytus et al., Brit. J. Pharmacol. 132:354-367 (2001)), which may be associated in the development of opioid tolerance and dependence (see also M. E. Fundytus, CNS Drugs 15:29-58, (2001)). Very recently, it has been shown that antisense oligonucleotide knockdown of mGluR1 attenuates the development of opioid tolerance (R. N. Sharif et al., Brit. J. Pharmacol. 136:865-872 (2002)). Selective antagonists of the mGluR5 receptor have also been shown to exert anti-dependence activity in vivo (C. Chiamulera et al., Nature Neurosci. 4:873-874 (2001)).
Without treatment, Parkinson's disease progresses to a rigid akinetic state in which patients are incapable of caring for themselves. Death frequently results from complications of immobility, including aspiration pneumonia or pulmonary embolism. Drugs commonly used for the treatment of Parkinson's disease include carbidopa/levodopa, pergolide, bromocriptine, selegiline, amantadine, and trihexyphenidyl hydrochloride. There remains, however, a need for drugs useful for the treatment of Parkinson's disease and having an improved therapeutic profile.
Currently, benzodiazepines are the most commonly used anti-anxiety agents for generalized anxiety disorder. Benzodiazepines, however, carry the risk of producing impairment of cognition and skilled motor functions, particularly in the elderly, which can result in confusion, delerium, and falls with fractures. Sedatives are also commonly prescribed for treating anxiety. The azapirones, such as buspirone, are also used to treat moderate anxiety. The azapirones, however, are less useful for treating severe anxiety accompanied with panic attacks. Antagonists of the mGluR5 receptor have also been shown to exert anxiolytic and anti-depressant activity in in vivo animal models (E. Tatarczynska et al., Brit. J. Pharmacol. 132 (7):1423-1430 (2001) and P. J. M. Will et al., Trends Pharmacol. Sci. 22 (7):331-37 (2001)).
Examples of drugs for treating a seizure and epilepsy include carbamazepine, ethosuximide, gabapentin, lamotrigine, phenobarbital, phenytoin, primidone, valproic acid, trimethadione, benzodiazepines, γ-vinyl GABA, acetazolamide, and felbamate. Anti-seizure drugs, however, can have side effects such as drowsiness; hyperactivity; hallucinations; inability to concentrate; central and peripheral nervous system toxicity, such as nystagmus, ataxia, diplopia, and vertigo; gingival hyperplasia; gastrointestinal disturbances such as nausea, vomiting, epigastric pain, and anorexia; endocrine effects such as inhibition of antidiuretic hormone, hyperglycemia, glycosuria, osteomalacia; and hypersensitivity such as scarlatiniform rash, morbilliform rash, Stevens-Johnson syndrome, systemic lupus erythematosus, and hepatic necrosis; and hematological reactions such as red-cell aplasia, agranulocytosis, thrombocytopenia, aplastic anemia, and megaloblastic anemia. The Merck Manual of Medical Information 345-350 (R. Berkow ed., 1997).
Symptoms of strokes vary depending on what part of the brain is affected. Symptoms include loss of or abnormal sensations in an arm or leg or one side of the body, weakness or paralysis of an arm or leg or one side of the body, partial loss of vison or hearing, double vision, dizziness, slurred speech, difficulty in thinking of the appropriate word or saying it, inability to recognize parts of the body, unusual movements, loss of bladder control, imbalance, and falling, and fainting. The symptoms can be permanent and can be associated with coma or stupor. Examples of drugs for treating strokes include anticoagulants such as heparin, drugs that break up clots such as streptokinase or tissue plasminogen activator, and drugs that reduce swelling such as mannitol or corticosteroids. The Merck Manual of Medical Information 352-355 (R. Berkow ed., 1997).
Pruritus is an unpleasant sensation that prompts scratching. Conventionally, pruritus is treated by phototherapy with ultraviolet B or PUVA or with therapeutic agents such as naltrexone, nalmefene, danazol, and tricyclic antidepressants.
Selective antagonists of mGluR5 have been shown to exert analgesic activity in in vivo animal models (K. Walker et al., Neuropharmacol. 40:1-9 (2000) and A. Dogrul et al., Neurosci. Let. 292 (2):115-118 (2000)).
Selective antagonists of the mGluR5 receptor have also been shown to exert anti-Parkinson activity in vivo (K. J. Ossowska et al., Neuropharmacol. 41 (4):413-20 (2001) and P. J. M. Will et al., Trends Pharmacol. Sci. 22 (7):331-37 (2001)).
Selective antagonists of the mGluR5 receptor have also been shown to exert anti-dependence activity in vivo (C. Chiamulera et al., Nature Neurosci. 4 (9):873-74 (2001)).
U.S. Pat. Nos. 6,156,908 and 6,492,541 B2 to Drauz et al. each disclose a procedure for the manufacture of 3-amino-2-oxo-pyrrolidines.
U.S. Pat. No. 6,248,756 B1 to Anthony et al. discloses nitrogen-heterocyclic compounds useful as farnesyl-protein transferase inhibitors.
International Publication No. WO 92/02502 by Smith Kline & French Laboratories Ltd. discloses N-hydrocarbyl-4-substituted piperidines useful as calcium blocking agents.
International Publication No. WO 99/37304 by Rohne-Poulenc Rorer Pharmaceuticals, Inc. discloses oxoazaheterocyclic compounds useful for inhibiting factor Xa.
International Publication No. WO 00/47553 by Cor Therapeutics, Inc. discloses alkynyl compounds useful for inhibiting factor Xa.
International Publication No. WO 01/17992 by Merck & Co. discloses pyrrolidine compounds useful for inhibiting prenyl-protein transferase.
International Publication No. WO 01/96331 by Bristol-Myers Squibb Co. discloses lactam compounds useful for inhibiting factor Xa.
There remains, however, a clear need in the art for new drugs useful for treating or preventing pain, UI, an addictive disorder, Parkinson's disease, parkinsonism, anxiety, epilepsy, a seizure, stroke, a pruritic condition, psychosis, a cognitive disorder, a memory deficit, restricted brain function, Huntington's chorea, ALS, dementia, retinopathy, a muscle spasm, a migraine, vomiting, dyskinesia, or depression.
Citation of any reference in Section 2 of this application is not to be construed as an admission that such reference is prior art to the present application.